Moving target screen

ABSTRACT

An electro-optical indoor training device which permits operators of one or more laser carrying weapons to aim at a realistic simulated target scene presented by a motion picture film projector. Each frame of the film contains a first portion representing a scene including at least one target area at which the laser beam of any given weapon should be directed and a second portion which is substantially opaque to laser radiation except for a transparent region thereof corresponding in location exactly to the location of the target area in the first portion of the film frame. Each weapon has a low power laser attached thereto which can be excited by actuating the weapon trigger and by automatic electronic delay, thereby firing the laser at previously determined time intervals; the laser beam, if properly aimed at preselected areas of the target scene on the projection screen, will be focused onto hit detection means, whereas an improperly aimed laser beam will impinge upon attempt detection means. Attempts and hits for all involved weapons are scored on an individual basis by electronic display means and electronic multiplexing means (when more than one weapon is to be fired) for synchronizing non-concurrent firing of the various weapons with film frame projection.

United States Patent Pardes et al.

[ MOVING TARGET SCREEN [75] Inventors: Herman I. Pardes, Wanamassa;

Joseph R. Schwartz, Neptune City; Frederick B. Sherburne, Oceanport, allof NJ.

[73] Assignee: The United States of America as represented by theSecretary of the Army, Washington, D.C.

[22] Filed: June 4, 1974 [21] Appl. No.: 476,238

[52] US. Cl. 35/25 [51] Int. Cl. F4ig 11/00 [58] Field of Search 37/25;273/l0l.l; 353/11, 353/29, 35, 43-44 [56] References Cited UNITED STATESPATENTS 3,802,099 4/l974 Mell et al 35/25 Primary ExaminerRobert W.Michell Assistant Examiner-John H. Wolff Attorney, Agent, or FirmNathanEdelberg; Robert P. Gibson; Daniel D. Sharp June 10, 1975 [57] ABSTRACTAn electro-optical indoor training device which permits operators of oneor more laser carrying weapons to aim at a realistic simulated targetscene presented by a motion picture film projector. Each frame of thefilm contains a first portion representing a scene including at leastone target area at which the laser beam of any given weapon should bedirected and a second portion which is substantially opaque to laserradiation except for a transparent region thereof corresponding inlocation exactly to the location of the target area in the first portionof the film frame, Each weapon has a low power laser attached theretowhich can be excited by actuating the weapon trigger and by automaticelectronic delay, thereby firing the laser at previously determined timeintervals; the laser beam, if properly aimed at preselected areas of thetarget scene on the projection screen, will be focused onto hitdetection means, whereas an improperly aimed laser beam will impingeupon attempt detection means. Attempts and hits for all involved weaponsare scored on an individual basis by electronic display means andelectronic multiplexing means (when more than one weapon is to be fired)for synchronizing nonconcurrent firing of the various weapons with filmframe projection.

8 Claims, 10 Drawing Figures IO SYNC. PULSE PROJECTOR 22 I47 [44 IF HITATTEMPT h DETECTOR DETEcTDR 62 WEAPON TRIGGER l POSITION SWITCH 461 l 47DEc0DER AMPLIFIER AMPLIFIER RF 66 RECEIVER X l l r 63 {65 HIT ATTEMPTTHRESHOLD THRESHOLD LASER DISCRIMINATOR ENABLE 52 I 53 5 SCORING LDISPLAY 83 eo WEAPON 8- POSITION e TRANSMITTER 73 ENCODER 87 PATENTEDJUHI 0 ms FIG. 1

IO SYNC. f PULSE PROJECTOR 22 HIT ATTEMPT DETECTOR DETECTOR 46 I IAMPLIFIER AMPLIFIER HIT ATTEMPT THRESHOLD THRESHOLD 52 53 f 5' SCORINGDISPLAY 83 WEAPON I;- POSITION bt i 73 ENCODER I I I I L TRANSMITTERSHEET 1 RF RECEIVER L WEAPON POSITION fjf gfi DECODER f 65 PULSE WIDTHLASER DISCRIMI NATOR ENABLE OUTPUT \To PROJECTOR OPTICS PATENTEDJUH 10I975 SHEET FIG. 3a

FIG. 3b

FIG. 40

FIG. 40

PATENTEDJUH ms 3.888,022

SHEET 3 FIG. 5

I a w I 73 74 I ONE SHOT I 5 M3 FLIP-FLOP SYNCH I I IN I 76 77 I GATEDPRESETTABLE I OSCILLATOR z ff I 83 I 84 7 L I ONE SHOT 1 I I 89 I j IONE SHOT I 87 I 82 LSI I 88 I h w TO scomme #I DECODER DISPLAY I W #aH-:coB2 T I one SHOT 4/92 I 9|? 93 I PRESET I I no I I COUNTER ONE SHOT I LI I L A g R I I I I ONE SHOT L 1 I I I J ONE SHOT ol I I 97 I =0 Q I I II IOB I II ONE SHOT I I/IO4 I I I 661 b: I I IJ- TRIGGET I 98 99 .91 II00 I ONE SHOT I Z I 1 I TO HIT I fi I LED I2 DECODER 1 MOVING TARGETSCREEN BACKGROUND AND SUMMARY OF THE INVENTION Existing training methodsin markmanship and firing tactics for combat troops, police, sportsmensclubs, and other similar groups, leave much to be desired from theaspects of realism, motivation. cost and practicality. Present firingranges are limited and sometimes inaccessible for reasons of priority,distance and weather. Except in the most sophisticated cases, thetargets are stationary and relative motion must be provided, forexample, by actual moving troops. Moreover, when live ammunition isused, expense, risks, and administrative problems increase considerably.For initial training in markmanship and tactics, it is preferred to havean indoor range where a squad of men can fire against realistic movingtargets from fixed positions.

The projection technique of the invention can provide multistation smallarms training at simulated target ranges of 50 to 300 meters or more inan indoor area no longer than meters in length. The technique providesinexpensive training in readily accessible locations, not suitable forlive firing, thereby eliminating many of the problems associated withrange coordination and safety. Moreover, no expenditure of ammunition isnecessary to achieve a high standard of individual and unit proficiency.

The moving target screen technique of the invention makes use ofmodified stereo optics in a standard motion picture projector to providethe imagery for the target scene and means for determing whether aweapon operator firing at the scene with a narrow laser beam from alaser attached to the weapon has hit the target. In this technique, amotion picture film is used on which the lower half of each framecontains a normal positive image and the upper half contains anannotated mask having an opaque background on which one or moretransparent apertures are located at the precise position where thetargets on the image appear. The apertured mask may be placed on thefilm strip by animation techniques, or other processes, on a frame byframe basis. The half of the frame containing the normal scene and theother half of the frame containing the apertures are both projected ontoa viewing screen.

The modified stereo optics normally provides two spaced projected frameson the viewing screen. These optics must be adjusted preliminarily todisplace one of the two projected frames relative to the other suchthat, at the screen, the aperture(s) on one projected frame aresuperimposed exactly on the corresponding target(s) on the otherprojected frame. In this manner, the aperture area(s) of the mask arefocused onto the corresponding target area(s) of the screen. A hitdetector then is pulled up into the film gate behind the aperture maskand the system is ready for operation. This detector is pulled out ofthe film gate during the previously described initial adjustment. Thefired laser beam, upon striking the surface of the screen, will beimaged onto the film mask. When the fired laser beam strikes a target onthe screen (which target has been previ' ously annotated on the mask)the laser beam energy reflects off this portion of the screen surface,and will, of course, be imaged onto the apertured portion of the filmmask; this reflected laser beam passes through the clear portion(aperture) on the film, and activates the hit detector positioned behindthe mask, thus registering a hit. A laser pulse striking off-targethowever, will be imaged on the opaque portion of the mask and will besufficiently attenuated to be below a preset threshold. A separate,wide-view detector can be positioned outside of the projector opticalsystem to receive laser energy reflected from the entire screen in orderto register attempts. For initial training purposes, the detector modulecan be moved out of the way and the weapon firers can view the relativeposition of the pro jected aperture areas and the projected scene todetermine which portion of the scene constitutes the actual target areato be aimed at.

In the case of single weapon firing, the output of the hit and attemptdetectors, after suitable amplification, would be applied to respectivehit and attempt threshold circuits feeding a single display counter.When the weapon firer actuates the trigger, a switch is closed whichpermits the laser to be pulsed. When more than one weapon firer isinvolved, each of the weapons becomes a part ofa digitally multiplexedtime sharing system. A series of shutter-synchronized clock pulses aregenerated in synchronism with projector film frame advance and processedwithin an encoder wherein, by discrete address techniques, each weaponis assigned a specific clock pulse within each time cycle, during whichthe laser on that particular weapon may be fired. The encoded output canbe either transmitted to a miniature receiver-decoder in each weapon orcoupled directly to a decoder in each weapon.

All laser pulses from a given weapon striking the screen (hits andmissed) are reflected onto the attempt detector and register on theattempt counter (display) for that weapon. The display is synchronizedwith the same encoder pulses as transmitted to the weapons, insuringthat each score displayed is from the particular weapon fired in thattime slot.

Real-time hit indication is provided to the firer by pulse widthdiscrimination techniques. When the threshold circuit records a hitduring a particular clock pulse, that pulse is electronically expanded.The receiver-decoder for that particular simulator recognizes theexpanded pulse and provides an indication to the firer by activating alight emitting diode (LED) located behind the rifle sight. Simulatorelectronics with the exception of the laser circuit, which is mounted onthe barrel can be mounted, for example, in a standard weapon magazineclip.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the systemaccording to the invention;

FIG. 2 is a view illustrating a portion of the projector optics of thesystem of FIG. 1, including a portion of the hit detector and means forgenerating a synchronizing pulse;

FIG. 3a is a view illustrating fundamentals of the projection optics,showing the position of the hit detector during preadjustment;

FIG. 3b is a view illustrating fundamentals of the projection system,showing the location of the hit and attempt detectors, during actualsimulated firing operation;

FIG. 4a illustrates a typical projection screen presentation prior toproper adjustment of the projection optics;

FIG. 4b illustrates a typical projector screen presentation after theprojection optics has been properly adjusted, with the detector in thenon-operating position;

FIG. 41 illustrates a typical projection screen presentation afterproper adjustment of the projection optics and after the hit detectorhas been moved to the operating position;

FIG. 5 is a block diagram of the encoder and decoder used in the systemof FIG. 1;

FIG. 6 includes a series of waveforms illustrating the operation of thesystem shown in FIGS. I and 5; and

FIG. 7 is a diagram illustrating a typical scoring display such as usedin the system of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION FIG. 1 of thedrawing illustrates a typical multiplexed time sharing system formulti-weapon operaton. A series of synchronizing pulses are derived fromthe projector l0 and applied to a weapon position encoder 50. Thesynchronizing pulses are proudced once during each revolution of one ofthe blades of the fan-shaped shutter 12 past the film image projectorgate 13, as indicated in FIG. 2. The projector can be any standardprojector which can be modified inexpensively and readily to permitinsertion ofa hit detector 14 in the region between the film 15 andprojector gate 13. Each frame of the film 15 of FIG. 2 must be rapidlymoved into the projector gate position and held more or less fixed inthat position for a discrete time interval, which by way of example, canbe 6 milliseconds; during this interval, the shutter 12 blocks lightemanating from the projection lamp 16. The film can be advanced in theprojector 10 of FIGS. I and 2 at the usual rate of 24 frames per second,so that the period between shutter sync pulses is substantially 42milliseconds. A twoblade shutter 12 is shown in FIG. 2 which blockslight from the projection lamp twice during each frame interval once forabout 6 milliseconds for frame position change, and again for about 8milliseconds to increase the flicker rate of the projected image, in thewellknown manner. The weapons are fired during the 8 millisecond periodwhen one of the shutter blades is in front of the projector lamp 16 andno light (or film image) is projected onto the viewing screen 30. Asshown in FIG. 2, a pin 17 mounted near the periphery of one of theshutter blades 12 cuts through a light beam created within the syncpulse generator unit 18. The latter unit is a commercially availableunit which includes a light emitting diode (see FIG. 2) mounted in onearm of the generator unit. The light beam, indicated by dotted lines ofFIG. 2, is directed across the gap between the arms of a generator unitI8 and impinges upon a photocell (not visible in FIG. 2) mounted in theopposite arm of unit 18. Also mounted within the upper arm is anamplifier from which a positive going waveform normally is derived. Whenthe light beam is cut by the shutter pin 17, however, a negative goingsync pulse (see waveform A of FIG. 6) is derived which appears at thesync pulse terminal 22 of generator unit 18.

As indicated in FIG. 3a, the projected image of each film frame of FIG.2 is projected onto the viewing screen 30 by conventional condensinglens means 24 and by way of a half stereo/reflector 25 consisting of twomirrors 26 and 27, one of which can be tilted relative to the other. Thegeneral direction of projection of the images onto the screen isindicated in FIG. 3a by the two solid arrows. The top and bottomboundaries of a given film frame is indicated by the small letters x andz in FIGS. 3a and 3b. The upper half yz of each frame of film on theprojector reel contains an inverted 5 normal positive scene, while theother (lower) half xy of each frame contains an annotated maskconsisting of a more or less opaque background in which there are one ormore clear (transparent) apertures 3i. As previously pointed out, theaperture or apertures 25 is located at the same relative position on themasked portion xy of each film frame as the corresponding target ortargets on the portion yz of that film frame containing the scene. Inthe particular example shown, the target area selected is the region ofthe mans chest. Consequently, the aperture 31 is located in the maskedportion xy of the film frame in the same relative region thereof thatthe region of the mans chest occupies in the image portion of the filmframe. If the target area were in the exact center of the film image,the aperture 31 in the masked portion xy would likewise be in the centerthereof, etc. Only half of a stereo/reflector is required in front ofthe projection lens 24 since a dualframe stereo format is not beingdisplayed.

Prior to actual operation, two complete single-frame format projectedimages XYZ and XY 'Z will be visible on the screen, as indicated in FIG.4a, owing to the presence of the two separate mirrors 26 and 27. Thepair of projected film frames (images) XYZ and X 'Y 'Z appear invertedon the screen from the position xyz actually occupied by the film on theprojector reel. The projected frames each includes a scene portion YZand Y'Z' and a masked portion XY and X'Y' within which respective brightspots 29 and 29' appear; obviously, only a bright spot is visible on thescreen within the rectangular confines indicated in FIGS. 40 and 4b asXY and KY. The bright spots 29 and 29' of the projected frames on thescreen will, of course, occupy the same position relative to the sceneas in the case of the film frame in the projector gate. By adjusting theposition of one of the mirrors, the two projected images XYZ and X'Y'Z'will be displaced relative to one another. The tiltable mirror 26 isadjusted until the bright spot in the annotated mask portion X'Y' ofimage X'Y'Z' is superimposed on the target (chest area of the man) inthe scene portion (Z of the projected image XYZ, as indicated in FIG.4b. During this procedure, the hit detector 14 of FIG. 1, also shown inFIGS. 2 and 3, is in the position indicated in FIG. 3a. After the properinitial adjustment of mirror 26 has been made, the hit detector 14 ispulled up by the handle 28 into the position shown in FIG. 3b, so as toblock light from lamp 16 from passing through the lower half of the filmgate, as indicated in FIG. 312. Now, as shown in FIG. 4c, only the sceneportion Y2 and Y'Z' of the projected image will appear on the screen 30and the bright spots 29 and 29' of XY and X'Y' of both projected imagesXYZ and X'Y'Z' are removed from the projection viewing screen 30. Theweapon firers thus see only the actual target scene on the screen,without any bright spots 29 formerly projected from apertured areas 31of the annotated mask portion xy of film frame xyz. Now that thepreliminary adjustments have been completed, the reeled film in theprojector is set in motion, thus providing the operators of the severalweapons 40 with one or more simulated moving targets at which to aimtheir weapons. The basic optics for the operating con dition are shownin FIGS. 1 and 3b. The laser beam from the laser 42, mounted as shown inFIGS. 1 and 3b, on the barrel 43 of weapon 40 is directed by thecorresponding weapon operator at the moving target on the viewing screen30. The laser 42 may, by way of example, be a 0.8l micrometer galliumaluminum arsenide laser with a beam spread of about 3 milliradians. Thelaser output is of the order of 6 watts in a I nanosecond pulse, and, assuch, presents no hazards to the eye of the oeprator(s). If a particularoperator's aim is proper, the laser beam will strike the area of theimage scene on the screen over which the bright spot in the annotatedmask portion of the image was previously superimposed. When the laserbeam strikes this area of the screen, that is, when the simulated targeton the screen has been hit," the beam will be imaged onto the film maskso as to pass through the clear portion (aperture) 31 of the maskportion xy of the film frame and will activate the hit detector 14positioned behind the film. In other words, if light passing through theaperture 31 in the mask portion xy of the film frame is imaged onto thedesignated target area of the image scene in the screen 30, then opticalenergy (from the laser gun) at the target area of the image screen will,by the principle of optical reciprocity, be imaged onto the aperture ofthe mask portion of the film frame in question. A laser beam strikingoff-target will be imaged onto the substantially opaque portion of themask, if not imaged off the film entirely, and will be sufficientlyattenuated to be below a preset threshold so as not to activate the hitdetector.

A separate attempt detector 44 which can be located outside of theprojector optical system, as indicated in FIG. 3b, can view the entirescreen and will respond to laser light reflected over an undefined fieldof view, as indicated schematically by the broad arrow 46 in FIG. 3b. Asshown in FIG. 1, the response indicated by the hit and attempt detectorsis amplified by respective amplifiers 46 and 47, and supplied torespective hit and attempt threshold circuits 48 and 49 which serve toinsure that the amplified output from the attempt detector isinsufficient to provide an output at the hit terminal 51. Although shownseparately in FIG. 1, the amplifiers 46 and 47 and threshold circuits 48and 49 may be packaged within the respective detectors 14 and 44, asindicated in FIGS. 30 and 3b. The hit detector, attempt detector andaccompanying amplifiers and threshold circuits can all be mounted withinthe body of the projector mechanical package 10. The hit and attemptpulses are applied to a scoring display 52 which will be described indetail in discussing FIG. 7 of the drawing. The sync pulses at terminal22 are supplied to the weapon position encoder 50 which is shown ingreater detail in FIG. and described in greater detail later. Theencoder 50 provides a pulse train of clock pulses for the n weapons tobe fired, each pulse train being synchronized with the synchronizingpulse from the projector 10. Each weapon simulator 40 is assigned aspecific one of said clock pulses within each time cycle, during whichtime slot the particular weaponmounted laser may be energized (fired).The encoder 50 also serves to expand electronically the clock pulsecorresponding to the particular weapon whenever the firer of that weaponhas hit the simulated moving target image on the screen 30. The encoderpulses are transmitted by way of a conventional transmitter 57 to thereceiving location 60 which involves a compatible receiver 6] and aplurality of weapon position decoders 62, one for each weapon to befired. Each weapon position decoder includes a pulse width discriminator63. These components at the receiving station, along with the laserenable circuit and trigger switch 66, can be disposed in a singlepackage physically mounted in the weapon magazine clip. In other words,the receiving location 60 shown within the dotted lines in FIG. 1 can bemounted within the clip 68 of the weapon 40, as indicated by the wavyline 69. The pulse width discriminator 63 for the particular weaponsimulator recognizes the received expanded pulse and supplies a pulsewhich activates a light emitting diode 71 mounted on the barrel of theweapon behind the weapon sight 72 to indicate to the firer that a targetbit has previously occurred.

The solid state laser 42, which is mounted to the barrel of the weapon40, is energized only after the trigger, physically a part of theweapon, is actuated to close the trigger switch 66 and when the laserenable circuit 65 simultaneously produces a suitable output (laserenable) pulse. The latter can occur only during that one of the n timeslots (n l2, in the case assumed) reserved for the particular weapon.

As will be explained during the description of the encoder-decodercircuit of FIG. 5, the output of the weapon position encoder 50 can behard wired to the input of the weapon position decoder 62, in which casethe transmitter and receiver can be omitted.

The operation of the system of FIG. 1 will now be described in greaterdetail by referring to the encoderdecoder circuit shown in FIG. 5 andthe waveforms derived at various portions thereof, as illustrated inFIG. 6.

The sync pulses (waveform A of FIG. 6) at encoder input terminal 73 areinverted by means of the NAND gate 74 and applied to flip flop 75 ofFIG. 5 which produces the waveform B of FIG. 6. The leading edge of thiswaveform from flip flop 75 initiates oscillations of the gatedoscillator 76 of FIG. 5. The gated oscillator output has a period of 500microseconds; the inverted output of this gated oscillator, appearing atthe output of NAND gate 77, is represented by the waveform C of FIG. 6.After receiving a given number of said inverted pulses from gatedoscillator 76, shown, by way of example, as twelve, the presettablecounter 78 produces an output (see waveform D of FIG. 6) which ispositivegoing at some selected time prior to l2 500 6 microseconds aftereach sync pulse, in the example assumed herein. Upon receipt of the 12thpulse of waveform C of FIG. 6 (6 milliseconds after arrival of the syncpulse), the output of binary counter 78, viz., waveform D of FIG. 6,goes negative. This negative-going output triggers a one-shot device 79the output of which (waveform E of FIG. 6) is used to reset the flipflop 75 so as to preset further oscillation of gated oscillator 76 andto reset binary counter 78 to await the start of the next operatingcycle commencing with the next sync pulse. The operating cycle is about42 milliseconds in the case of a standard projector with 24 frames persecond. The one-shot 79 serves to limit to twelve the number of pulsescoming from the gated oscillator 76 and counted by the binary counter78. The twelve pulses (waveform C of FIG. 6) are applied sequentially tothe one-shot 81 where pulses are obtained (waveform F of FIG. 6) whichare, for example, 200 per seconds wide and occur at a pulse rate of 500microseconds. These negative-going pulses F are available at encoderoutput terminal 88 and are applied to the scoring display 52. Thenegative-going pulses F are also applied directly to one input terminalof the NAND gate 82. When a hit pulse is derived during, say, the 8thpulse time interval as a consequence of the tirer of weapon number 8properly aiming the laser gun at the moving target on the projectorscreen. this hit pulse appearing at encoder input terminal 83, afterpolarity inversion in NAND gate 84 (see the waveform G in FIG. 6) issupplied to one-shot 85 to provide negative-going output (waveform H ofFIG. 6) which serves as the other input to NAND gate 82. The waveform Hof FIG. 6 from oneshot has a pulse width of 300 microseconds, ascontrasted with the 200 microsecond width of the other eleven pulses ineach pulse train.

The operation of the NAND gate 82 is such that an output pulse (waveformJ of FIG. 6) appears at the output terminal 87 of the encoder 50whenever a negativegoing pulse appears at either or both input terminalsof the NAND gate 82. In the example given, the output of encoder 50 willbe a train (waveform J) of 12 pulses which, except for the eighth pulse,are of 200 microseconds duration; the eighth pulse, created by thesimultaneous presence at the NAND gate 82 of the eight outputZOO-microsecond pulse (eighth pulse in waveform F of FIG. 6) from theone-shot 81 and the 300 microsecond pulse (the waveform H of FIG. 6) is,of course, 300 microseconds wide.

The encoder output pulses at terminal 87 can be transmitted by means ofa transmitter 57 to the decoder 60, as indicated in FIG. I. The outputof the transmitter to the decoder falls to zero during each pulseinterval of 200 or 300 microsecond, as the case may be. The transmittedencoder output at terminal 87 can be received by an appropriate receiver61 and the output of the receiver (substantially identical to waveform Jof FIG. 6) is applied to the input terminal 90 of the decoder 62.

It should be pointed out that, in some cases, the transmitter-receiverbetween the encoder and decoder, such as shown in FIG. I, may bereplaced by the directly-wired connection, 89, illustrated in FIG. 5.Generally, however, it is preferrable to use the radio link rather thanthe more cumbersome hard wiring between the encoder and each of theseveral weapon decoders. The encoder output (waveform J), or the outputof receiver, as the case may be, is applied to presettable counter 91which is preset so that the counter output swings negatively uponreceipt of (m-l) pulses from the encoder 50 where the decoder is the nthdecoder (corresponding to the nth weapon to be fired). For example, forthe eighth decoder corresponding to weapon number eight of the twelveweapons, the counter output (waveform K of FIG. 6) swings negativelyupon receipt of the seventh input pulse.

The trailing (positive-going) edge of the output pulse (waveform K ofFIG. 6) from the preset counter 91 is used to trigger a one-shot 92which produces a reset pulse (waveform L of FIG. 6) for resetting thecounter 91 and thereby prevent further counting of incoming pulses fromthe encoder 50 until the arrival of the next train of l2 pulses. Thisreset waveform L of FIG. 6 returns shortly thereafter to its morepositive value which is retained until arrival of the trailing edge ofthe next output pulse from counter 91. The preset counter output pulse(waveform K of FIG. 6) is supplied also to one-shot 93 which providesone of the input pulses 8 (waveform M of FIG. 6) to the output NOR gate94. By way of example, the pulse M is 60 microseconds wide.

The present counter output pulse also is applied to a pulse widthdiscriminator 95 comprising two serially connected one-shots 96 and 97.The first of these oneshots, viz., one-shot 96, is triggered by theleading edge of waveform K and provides a pulse (waveform N of FIG. 6)of approximately 240 microseconds width. The trailing edge of the pulseN then triggers the second one-shot 97 from which a narrow pulse(waveform P of FIG. 6) of approximately l0 microseconds is obtained. Thepulse P and the pulses J from the encoder are applied to the NOR gate98. The pulses P do not arrive at NOR gate 98 until 240 microsecondsafter the beginning of the n=8th time slot, which is essentially 240microseconds after arrival of the hit pulse at the hit input terminal 83of the encoder 50. Obviously, none of the normal ZOO-microsecond pulsesJ will appear at NOR gate 98 concurrently with the delayed pulse I;thus, there will be no positive-going output (waveform R of FIG. 6) fromNOR gate and the one-shot 99 will remain in the normal negative state(see waveform S of FIG. 6).

If, however, a hit pulse occurs at hit input terminal 83 of the encoder,resulting in the presence of a negativegoing pulse of 300 microsecondsduration, a 300 microsecond pulse J appears at one input to NOR gate 98and will occur simultaneously with the other input pulse P. Theresulting positive-going pulse (waveform R of FIG. 6) of 10 microsecondswidth will trigger the one-shot 99 and provide a positive-going pulse(waveform S of FIG. 2) of sufficient duration and amplitude at decoderterminal 100 to energize the light emitting diode 71 on thecorresponding weapon. This lightemitting diode 71 indicates to the firerof that weapon that he has scored a hit on the simulated target on thescreen 30.

When the operator of the number 8 weapon actuates the trigger, that is,closes trigger switch 65, provided that the test switch 103 and switch104 are in the closed (left hand) position in FIG. 5, the clock input(input to terminal C) of flip flop 105 is generated by virtue of thecharging current flowing through the RC circuit 107 as a result of thepotential appearing at the positive (Vcc) terminal of the flip flop 105and ground. The 6 or zero output of flip flop 105 goes negatively for aperiod determined by the time constant of the RC circuit 107. The flipflop 105 is reset by the arrival of the following pulse (wave form M ofFIG. 6) from the one-shot 93, that is, the 0 output thereof returns toits normal more positive state, as shown by the waveform T of FIG. 6.The one-shot 108, like the other one-shots and the gates, can be usedfor waveform sharpening. During the simultaneous presence at NOR gate 94of negativegoing pulses M and T, an output pulse (waveform U of FIG. 6)appears at the output (laser fire) terminal 1 ll of decoder 62. Thisoutput pulse U triggers the laser 42 on the corresponding number 8weapon 40 into production of a laser beam which then can be directed bythe weapon firer toward the simulated target on the screen.

A typical scoring display 52 located at the transmitting station isshown in FIG. 7 an includes a multi-stage binary counter and a decoder117, as well as an array of n hit counters [20a to :1 and an array of inattempt counters 1300 to one for each of the n weapon positions.

In the example given. i.e., where "=12, the binary counter 115 wouldhave four stages, so that 2 =l6 different output states would beavailable; of these, obviously only twelve are needed. A typical binarycounter 115 is illustrated on page 95 and described on pages 94 and 95of Digital Computer Fundamentals by Thomas C. Bartee, 2nd edition,published by McGraw- Hill Book Company in 1966. As each pulse (waveformF of FIG. 6) arrives at the binary counter 115, the Q or ONE output fromeach counter stage is complemented and a different combination of ONESand ZEROS appear at the four stages. For example, upon receipt of thesixth pulse from encoder terminal 88, the outputs of the four counterstages, in the order of increasing significance, will be lOlO. Thedecoder 117 of FIG. 7 essentially consists of a group of separate gateseach connected to an appropriate combination of the Q output terminalsof the flip flops in the binary counter 115. For example, an AND gateconnected to the Q output terminals of the second stage and the fourth(most significant) stage of the binary counter 117 will provide anoutput which occurs only in response to the 6th pulse (waveform F) fromthe encoder 50. Similarly, only the output terminal of the fourth stageof the flip flop would be connected to the AND gate whose outputrepresents the arrival of the 8th pulse F from encoder 50, etc. Thistype of decoder circuitry is well known, and is illustrated in pages2-l03 of Vol. 2 of Basics of Digital Computers" by Murphy, published in1958 by John F. Rider Publisher, lnc.

The separate AND gate outputs in the decoder 117 for each of the n=l2weapon positions is connected by a separate line to both a correspondingNAND gate 122 in the array of hit counters 120 and to a correspondingNAND gate 132 in the array of attempt counters 130. For example, the 8thpulse corresponding to weapon number 8, from the decoder 117, isconnected by line 118 to the eighth NAND gate 122/: in the scoringdisplay console which is connected to the hit counter 12011 for weapon 8and also to the eighth NAND gate 132/: in the scoring display consolewhich is connected to the attempt counter 13011 for weapon number 8.Similar connections are shown in FIG. 7 for two other weapon positions,namely l and 12. The hit detector terminal 51 is connected to an inputterminal of all NAND gates 122 for the hit counter array 120 while theattempt detector terminal 52 is connected to the input terminal of allNAND gates 132 of the attempt counter array 130. If the firer of weaponnumber 8 scores a hit, a hit pulse G at the hit detector terminal 51will be available at all NAND gates 122. However, only the NAND gate122/? for the number 8 weapon position of the hit counter 120 array willboth input lines active. Consequently, the hit counter 12011 forposition number 8 will be activated upon arrival at the incoming hitpulse at hit detector terminal 51. Similarly, if the firer of weaponnumber 8 misses the simulated moving target on the screen, only laserenergy reflected from the screen onto the attempt detector 49 would besensed and an attempt pulse would appear at the attempt dctectorterminal 53; this attempt detector pulse, in combination with the pulsefrom decoder 117 of FIG. 7, would open NAND gate 13211 and activate theattempt counter 130): in the scoring display corresponding to attemptcounter array position number 8. Obviously. a counter 120 and thecorresponding attempt counter 130 for any given weapon will be activatedeach time the flrer of that weapon actuates the trigger. The hitcounters and attempt counters of FIG. 7 can be any of several well knowntypes of high speed electronic counting devices which can include one ofmany types of digital display tubes by means of which the total numberof attempts and misses by each of the n weapon firers can be observed atany instant of time. It is possible to design the circuitry of thescoring display 52 so that a hit pulse must be coincident with anattempt pulse in order to register a hit on the hit counter. In thismanner, any ambiguities owing to random spurious pulses of rather largeamplitude will not provide an erroneous hit count on the moving display52.

Obviously, many modifications and variations of the present inventionare possible. The scope of the invention is limited only in the mannerdefined by the claims.

What is claimed is:

1. An electro-optical weapon firing training device comprising a filmstrip projector and viewing screen, at least one weapon on which ismounted a laser means to trigger a laser beam upon firing said weapon, afilm strip, each frame of said film strip containing a first por tionrepresenting a scene including at least one target area at which thelaser beam should be directed and a second portion which issubstantially opaque to radiation from said laser except for at leastone aperture region through which light from said projector can pass,the location of said aperture within said second portion being in thesame relative position as the location of the target area in the firstportion of said film strip, said projector including optical means forprojecting each frame of said film strip onto said screen as twoseparate projected frame portions each having a scene portion and abright spot whose location relative to the projected scene portion isthe same as that of the aperture region relative to the first portion ofsaid film frame, and including adjustable means for initially moving oneprojected frame portion on the screen relative to the other projectedframe portion on the screen until the aperture region in the secondprojected frame portion is superimposed exactly on the correspondingtarget area in the scene portion of the other projected frame portion,and means responsive to correspondence between the position of the laserbeam impingement upon said screen and said bright spot.

2. An electro-optical weapon firing training device according to claim 1further including a hit detector moved into an operating positionblocking that portion of the aperture gate of said projector which isjuxtaposed to said second portion of a given frame of the film strip,whereby only the scene portion of said one projected frame is visible onthe screen.

3. An electro-optical weapon firing training device according to claim 2wherein said hit detector is pulled out of said projector aperture gateduring the aforesaid initial relative motion of the projected frames onthe screen effected by said adjusting means.

4. An electro-optical weapon firing training device according to claim 2wherein the laser radiation reflected only from that portion of thescreen on which the target area of the projected scene appears will beimaged onto the transparent aperture region of said second portion ofthe film frame at the projected aperture gate and will impinge upon saidhit detector.

5. An electro-optical weapon firing training device according to claim 2further including a wide-angle attempt detector positioned outside theprojector optical system and responsive to laser energy reflected fromthe entire screen to register operator firing attempts.

6. An electro-optical weapon firing training device according to claimfurther including separate counting display means responsive to theoutput of the corresponding hit and attempt detectors.

7. An electro-optical weapon firing training device according to claim 1wherein a number of n laserbearing weapons are used, each weapon havinga trigger under control of the operator of the weapon, further includingmeans for generating n synchronizing pulses of repetition rate equal tothe projector frame rate, a weapon position decoder for each of saidlaserbearing weapons, each decoder responding to one only of said clockpulses to provide a laser enable pulse to the laser of the correspondingweapon, the laser of said weapon producing a laser beam uponsimultaneous receipt of said laser enable pulse and actuation of theweapon trigger.

8. An electro-optical weapon firing training device according to claim 7wherein said encoder includes a pulse expander for increasing the widthof that clock pulse which occurs coincidentally with a hit pulse fromthe hit detector and said decoder includes a pulse width discriminatorfor deriving an output therefrom only in response to said clock pulse ofexpanded width, a light emitting diode mounted on each weapon andresponding to the output from said pulse width discriminator to indicateto the operator of that weapon that the simulated target area on thescreen has been hit by the laser beam mounted on that weapon.

1. An electro-optical weapon firing training device comprising a filmstrip projector and viewing screen, at least one weapon on which ismounted a laser means to trigger a laser beam upon firing said weapon, afilm strip, each frame of said film strip containing a first portionrepresenting a scene including at least one target area at which thelaser beam should be directed and a second portion which issubstantially opaque to radiation from said laser except for at leastone aperture region through which light from said projector can pass,the location of said aperture within said second portion being in thesame relative position as the location of the target area in the firstportion of said film strip, said projector including optical means forprojecting each frame of said film strip onto said screen as twoseparate projected frame portions each having a scene portion and abright spot whose location relative to the projected scene portion isthe same as that of the aperture region relative to the first portion ofsaid film frame, and including adjustable means for initially moving oneprojected frame portion on the screen relative to the other projectedframe portion on the screen until the aperture region in the secondprojected frame portion is superimposed exactly on the correspondingtarget area in the scene portion of the other projected frame portion,and means responsive to correspondence between the position of the laserbeam impingement upon said screen and said bright spot.
 2. Anelectro-optical weapon firing training device according to claim 1further including a hit detector moved into an operating positionblocking that portion of the aperture gate of said projector which isjuxtaposed to said second portion of a given frame of the film strip,whereby only the scene portion of said one projected frame is visible onthe screen.
 3. An electro-optical weapon firing training deviceaccording to claim 2 wherein said hit detector is pulled out of saidprojector aperture gate during the aforesaid initial relative motion ofthe projected frames on the screen effected by said adjusting means. 4.An electro-optical weapon firing training device according to claim 2wherein the laser radiation reflected only from that portion of thescreen on which the target area of the projected scene appears will beimaged onto the transparent aperture region of said second portion ofthe film frame at the projected aperture gate and will impinge upon saidhit detector.
 5. An electro-optical weapon firing training deviceaccording to claim 2 further including a wide-angle attempt detectorpositioned outside the projector optical system and responsive to laserenergy reflected from the entire screen to register operator firingattempts.
 6. An electro-optical weapon firing training device accordingto claim 5 further including separate counting display means responsiveto the output of the corresponding hit and attempt detectors.
 7. Anelectro-optical weapon firing training device according to claim 1wherein a number of n laser-bearing weapons are used, each weapon havinga trigger under control of the operator of the weapon, further includingmeans for generating n synchronizing pulses of repetition rate equal tothe projector frame rate, a weapon position decoder for each of saidlaser-bearing weapons, each decoder responding to one only of said clockpulses to provide a laser enable pulse to the laser of the correspondingweapon, the laser of said weapon producing a laser beam uponsimultaneous receipt of said laser enable pulse and actuation of theweapon trigger.
 8. An electro-optical weapon firing training deviceaccording to claim 7 wherein said encoder includes a pulse expander forincreasing the width of that clock pulse which occurs coincidentallywith a hit pulse from the hit detector and said decoder includes a pulsewidth discriminator for deriving an output therefrom only in response tosaid clock pulse of expanded width, a light emitting diode mounted oneach weapon and responding to the output from said pulse widthdiscriminator to indicate to the operator of that weapon that thesimulated target area on the screen has been hit by the laser beammounted on that weapon.